<!DOCTYPE html>
<html lang="en">
<head>
    <meta charset="UTF-8">
    <title>类选择器</title>
    <link rel="stylesheet" href="./css/style.css">
</head>
<body>
<h1 class="h11" id="h11">h1</h1>
<h1 class="h12">h1</h1>
<h1 class="h12">h1</h1>
<p class="p1">pppfdpdf</p>
</body>
</html>